Is using tealight candles to heat your room energy efficient?

In a word, No! ... despite the internet craze of using clay flowerpots to store and dissipate the heat energy from burning tea light candles.

The first law of thermodynamics, also known as Law of Conservation of Energy, states that energy cannot be created or destroyed in a chemical reaction. This means that no matter how efficient our flowerpot system is at dissipating the heat, the most energy we can hope to use to heat our room is the amount of energy available in the tea light. This amount energy will be released whether we burn the naked tea light or use it inside our flowerpot meaning that the room will be heated by the same amount.

Tea light candles have about 14g of paraffin wax in each which equates to around 0.179 kWh per tea light.[1] A quick search on the net gives current prices around £3 for 100 tea lights which works out to be around 17 pence per kWh. With competitive electricity prices being around 10 pence per kWh and gas around 2.5 pence per kWh, tea light power might not be the best way forward for heating your home! This is without taking into account that if you’re burning a lot of these things you’d better have good ventilation or an open window to let all the fumes escape. If you’re hoping to heat your room or house, then you’d be much better off using traditional heating methods!

That said, if you’re not hoping to heat your room by candle power and would just like a little heat on your desk, tea light candle heaters might not be as crazy as they seem. For someone like myself that spends a lot of time sat in front of a computer either working, studying or gaming, my hands spend a lot of time exposed at the keyboard. I can certainly see the attraction of having something to warm my hands on at my desk without having to heat up the rest of the room. While they might not start a nostalgic energy revolution, tea light heaters, such as the Egloo, may find themselves a niche desktop market.

Comments

Thank you for your comment. 13-14p is a competitive TCR (Tariff Comparison Rate). A tariff comparison rate assumes an average consumption of kWh and then includes the unit rates and standing charges.

For unit rates you can get rates of around 10p per kWh depending on the tariff, example. Granted this doesn't take into account standing charges, but I don't think many people would be cutting off their electricty all together, so these would still apply.